This invention is an improvement over applicants' assignee's U.S. Pat. No. 3,634,588 issued Jan. 11, 1972 to Steitz et al and U.S. Pat. No. 3,777,040 issued Dec. 4, 1973 to Gell et al.
Although electrodes of this type with ceramic-coated metal sleeves and water jackets are known according to the above mentioned patents, neither of these patents include the specific improved coating, sealing and centering means for the sleeve and jacket invented and disclosed herein by applicants.